BIRDS OF MARSHALL COUNTY 133 



for each day. They were not recorded ag-ain until April 12 

 and 13 when they were common on both dates. They were then 

 absent until April 19, when a single bird was noted. These birds 

 became common on April 20 and are marked common until April 

 27, but with explanatory^ notes. Thus on the 23d a note says 

 "greatly increased." That is, they were common from April 

 20 to 23, but their numbers increased notably on the 23d. 

 Again they are noted "greatly increased'' on May 2, a date 

 which marked the end of the noticeable fluctuations until the 

 breeding season begins. The data for this species in 1914 and 

 1915 show the same fluctuations in numbers. 



Many interesting things were noted during these migration 

 studies, full discussion of which must be reserved, however, for 

 a future paper, but a few of the more interesting are included 

 here. 



Late August and early September of both 1913 and 1914 were 

 marked by enormous flocks of sandpipers which were feeding on 

 exposed mud flats around the Goose ponds. These flocks were 

 composed principally of pectoral, least, semipalmated, solitary, 

 and spotted sandpipers, and yellowlegs. In addition many 

 others, including the white-rumped and Baird's sandpipers, 

 killdeer and semipalmated plover, appeared regularly and some- 

 times in considerable numbers. These flocks were tame and 

 aiforded an unusual opportunity for close comparative study. 

 As far as possible the opportunity was used and many houre 

 were spent watching the various activities of the different 

 species. 



In 1914 the usual spring flood of Iowa river failed to mate- 

 rialize and the migrating ducks instead of spreading out over 

 hundreds of acres of flooded fields were compelled to remain in 

 the river proper. The Federal migratory-bird law prohibiting 

 spring shooting was in force for the first season and it was very 

 generally observed. Whether or not this had any relation to 

 the numbers of the ducks, the fact remains that more waterfowl 

 were seen during this season than in several previous years spent 

 in various parts of Iowa. As these ducks were practically 

 unmolested they became very tame and remained until long 

 after the usual time of departure for the north. Many species 

 remained until May 1 or later and practically all the latest spring 

 records given in the annotated list were obtained in this year. 



